Telegraph printer



Sept. 26, 1944. L. M. POTTS TELEGRAPH PRINTER Original Filed May 9. 1940 4 Sheets-Sheet l INVENTOR.

, LOUIS M. POTTS A TORNE Y.

Sept. 26, 1944. -rs Re. 22,550

TELEGRAPH PRINTER Original Filed May 9. 1940 4 Sheets-Sheet 2 INVENTOR.

LOUIS M. POTTS A TTO/PNEY Sept. 26, 1944. 1.. M. POTTS TELEGRAPH PRINTER Original Filed May 9, 1940 4 Sheets-Sheet 3 INVENTOR. LOUIS M. POTTS ATTO/QNEY Sept. 26, 1944. L. M." PoTTs TELEGRAPH PRINTER Original Filed May 9. 1940 4 Shaets$heet 4 CODE COMBINATKN l-Il'lIII'IBIEIl-I FIG. l3

I'NVENTOR LOUIS M. POTTS ATTORNEY Reissued Sept. 26, 1944 UNITED STATES I Re. 22,550

PATENT OFF ICE TELEGRAPH PRINTER Louis M. Potts, Evanston, 111., alslgnor to 'l'eletype Corporation, Chicago, 111., a corporation of Delaware 12 Claims.

The present invention relates to printing telegraph apparatus and more particularly to type wheel printers having a plurality of printing positions.

The principal object of the present invention resides in the provision of printing and selecting apparatus designed to enlarge the range of selective possibilities without extensive modification of fundamental practices in printing telegraph selecting apparatus and without having to change the essential mechanism.

The use of a plurality of case shift signals in controlling the operation of telegraph printing apparatus is generally known but certain novel aspects herewith introduced have to do with a conversion system for adapting existent practices in design and manufacture of type wheel printers to the use of a greater number of case shift control functions. As an incident to this practice, there is contemplated under one embodiment the utilisation of a six-unit code for the supervision of apparatus constituted essentially of a five-unit selection and control mechanism, the presence or absence of the sixth impulse being a determining factor in establishing a secondary case shift control while the conventional pair of case shift signals are utilized additionally to the said sixth impulse case shift control for performing the primary case shift supervision. As a result, four instead of only two case shift conditions are provided, and these with but minimum modification in the essential design of a type wheel printer, such as that disclosed in copending application Serial No. 193,642, filed March 3, 1938.

In a type wheel printer of the design herein contemplated, the type wheel carrying shaft is a frictionally driven member surrounded by a number of parallelly disposed selector pins. A shaft stop arm engages one of these pins when any of the latter is brought into selective condition established by an individual disposition of live selector discs, each provided with peripherally disposed notch and lug attributes, and the several adapted to be moved in response to the selective operation of a line signal supervisedtransfer mechanism.

In addition to carrying the type wheel and .accordingly positioning the latter angularly so as to present predetermined type faces into printing position, the typ wheel carrying shaft is also utilized for supporting and rotating with it divers incidental function performing interponent elements. When certain one or ones of said elements are arrested in predetermined angular positions as controlled by the type wheel shaft arresting apparatus, there are conditioned corresponding one or ones of several function performing levers for executing miscellaneous incidental operations; viz., primary case shift, carriage return, etc.

An additional set of case shift control functions identified as secondary to the conventional case shift operation is contemplated such that their incorporation into existing apparatus may permit of an enlargement of several selective possibilities to an extent of doubling the available selective possibilities based on previous practice.

For a more comprehensive understanding of the present invention, reference may be had to the accompanying drawings and to the detailed specification following hereinafter in which similar reference characters indicate corresponding parts throughout, and in which:

Fig. 1 is a vertical sectional view through a printing telegraph apparatus, such as that featured in the copending application mentioned above, having incorporated therein the improvements which exemplify one embodiment of the instant invention;

Fig. 2 is a plan sectional view taken approximately on line l---! of Fig. 1;

' Figs. 3 to 8 are detailed views of the case shift determining apparatus featured in Figs. 1 and 2;

Fig. 9 is a schematic diagram of a first modiflcation of the invention which utilized plus, minus, and n'o-current for signal composition with the marking impulses varying between positive and negative current characteristics for the purpose of obtaining a shift control index;

Fig. 10 illustrates a modified form of shift mechanism especially adapted for use in a system such as that featured in Fig. 9;

Fig. 11 is a fragmentary plan section'of a second modification apparatus;

Fig. 12 is a schematic diagram of a system which uses an apparatus of the type shown in Fig. 11 in which the signals are of conventional length, but in which a sixth impulse is incorporated with the stop interval and the start impulse is varied to contrast with the stop'impulse; and

Fig. 13 is a diagrammatic chart of a code si nal such as may be used in the system disclosed in Figs; 11 and 12 showing how its component parts are functionally allocated.

In illustrating the preferred embodiment of the present invention, Figs. 1 to 4, a typ wheel page printing machine is used whose selector at whose upper extremity is carried a cylindrical type supporting wheel having individually movable printing pallets. This type wheel indicated II is provided with four annular rows of type pallets l2, each pallet of which is radially slidable within its own confining groove, and each annular row of which is retained and urged towards the concentric center of the wheel by a garter spring II. A cylindrical printing platen I4 is Journaled upon a supporting shaft i and is shiftable endwise step-by-step in one direction in response to printing operations, and totally in the other'direction in response to a carriage return signal in a manner well-known among page printing machines.

The platen I4 is supported in a carriage generally indicated II which may itself be supported and confined by antifriction rollers i1 confined between the trackways l3 and i9. In-front of the printing platen i4, there is indicated a printing ribbon 2|, the location of which, with respect to the periphery of platen I4, is indicative of the printing locus and, accordingly, denotes the level at which each row of printing pallets must be aligned in order to present it into printing engagement with said platen l4.

The type wheel Ii is integrally associated with a supporting collar 22, and i splined to rotate with the type wheel shaft 23 but free to be shifted longitudinall thereof together with its collar 22. This longitudinal shifting of type wheel II is executed through engagement of a shifting frame 24 whose horizontal bar 23 is slotted as at 23, Fig. 2, to straddle and be received within the groove 21 of collar 22. For purposes of steadying the shifting frame 24, its bar 25 is provided at remote ends with yokes 23, Fig. 2, of which one is visible in Fig. 2, and which is indicated thereat 23 straddling the supporting column 29, parts 23 and 23 being duplicated at the opposite end of bar 25, but being broken away in the limited disclosure of Fig. 2.

Collar 22, Fig. 1, is prevented from rotating with respect to shaft 23 by the interengagement between its slide engagement coupling bar 3i with shaft is maintained in a vertical position, andwell as certain supporting apparatus has been eliminated from view in order to render more clear for observation that mechanism which is directly concerned with the present improvement.

when shaft 23 is so arrested, driven wheel 33 may continue to rotate, but slippa e is permitted between the latter and its adjacent driving discs 33 and 33 because of the intervening slip washers 4 I, fibrous elements which are tensioned between the adjacent surfaces of gear wheel 33 and said discs 33 and 33. As explained in greater detail, in the above referred to copending application, the rotary drum selector which includes the above-mentioned selectable pins 31 is designed to accommodate a five-unit code having as its essential selector apparatus five circular discs 42 whose peripheries are provided with a notch and lug distribution, so that upon each permutative that 32 of a selector ann sleeve 33. Because of I the tongue and groove engagement between arms 3| and 32, type wheel ll, together with its collar 22, may be shifted longitudinally, without disengagement of driving connection between said elements 3| and 32, but permitting, nevertheless, of axial shifting of the type wheel and its associated elements throughout a distance sufficient to elevate the type wheel to the dotted outline position (of Fig. 1) while still maintaining the driving and driven relationship between the selector arm sleeve 33 and the type wheel I I.

Sleeve 33 and its integrally associated selector arm 34 are bound to the shaft 23 so as to rotate with it under impetus of the driven gear wheel 33 which maintains meshing engagement with the motor driving worm 36, but because selector arm 34 may be obstructed by one or another of the plurality of selectable pins 31, the assembly, including shaft 23, may thereby be arrested at any one of several radial positions corresponding with the several selectable pins 31. In passing, mention is made of the scant showing of a selector pin assembly in Fig. 1. Actually this apparatus consists of possibly thirty-two pins 31 all similarly held and the several closely placed in a circular group about shaft 23 as a center. The single pin 31 illustrated in this figure denotes the relative position, but the others of the selector pins as placement of the several discs 42 an individual clearance is afforded to one of said several selectable pins 31 which, when that occurs, moves inwardly to present its upper extremity, Fig. 1, into the path of rotatable arm 34, blocking the further progress of said arm and through it the rotation of shaft 23.

This selection, arresting shaft 23 in any of thirty-two rotary positions, may not only serve to align a corresponding printing lug II for subsequent printing operation, but also, because shaft 23 is a carrier of other selecting apparatus, it may serve to condition special function operating members as more fully described in said copending application. Of these special functions, certain ones only are concerned in the instant disclosure, and these will be identified as the two primary case shift functions; namely, the conventional upper and lower case shifts. In Fig. l, the two selectable bars which execute these case shift functions are illustrated in the lower portion of the figure by the reference numerals 43 and 44, the former having a sidewardly extending lug 45, and the latter a similar lu denoted 43.

The apparatus now described is that which, in response to the two conventional case shift signals, exercises a part supervision in determining the extent of vertical shifting of the type wheel II. The copending application referred to explains how, in response to the conventional case shift signals, bars 43 or 44, depending upon which of the two signals is received, rotates about a pivot located at its left extremity, Fig. 1, so as to present one or another of the lugs 45 and 46 forwardly. When bar 43 is thus selected and its lug 45 moves forwardly, there follows towards the conclusion of its selection cycle a rightward movement of all of the bars, including 43 and 44, so that lug 45 being the only one in extended position, is made to engage the lowermost extremity 41 of a shifting lever 43 whose opposite end being provided with the open slot 43 and straddling the stud pin SI of case shift plate 52 causes the latter to be moved leftwardly or into the position illustrated in Fig. l. The immediate significance of this movement is its characteristic placement horizontally of the anchor pivot 33, see also Figs. 3 and 4, but a further consequence of this operation will be discussed later.

Alternatively, upon. the selection of the other shift bar 44 and the consequent movement of its lug 48 into the path of the lowermost extremity 54 of lever 55, there results the movement of case shift plate 52 rightwardly to an extent of movement as denoted by the elongated hole 36 and the consequent restoration of case shift lever 48 to its sasso first position, since the twolevers l8 and II are articulated to the common pivot shaft I1, each serving to restore the other upon its selection. The result of the operation of lever II so far as the specific contemplation is concerned is in the movement of said pivot stud 53 rightwardly for a purpose to be discussed later.

Pivot screw 53, which has already been introduced above, constitutes a critical center and pivot support for an important element in the shift mechanism, namely, bell crank lOl-IM, about which more will be said later. Moreover, this key pivot is anchored in a sidewardly extending shelf I04, Figs. 3 and 4, which is integral with the shift plate 52 whose progress from side to side is governed by the selectable levers 43 and N as just described. When either of its alternative positions is established, shift plate 52 is thereat detained by the action of a spring loaded detent lever 5|) which is pivoted to the plate 52 at ill so as to urge with its V-shaped extremity against one side or the other of a fixed rod 10. When moved to its opposite position from either, lever 50 is cammed about pivot ill through cooperation of its V-shaped nose and said rod Ill.

Referring now again to the vertical shifting frame ll which carries with it the type wheel I I, it will be noted that its side wall, Fig. 1, contains an irregular aperture 58 whose lower edge provides two shoulders or steps indicated 59 and El seen also inv Figs. 5 to 8. The movement of frame 24 is maintained in a parallel vertical direction not alone by the aforedescribed alignment studs 28 but also because of shaft 51, one end of which is rigidly anchored-in the framework and the surrounding roller sleeve carried by said shaft fits closely within the confining slot 82 of framework 24. The frame 24 is lifted by means of an integral ear B3 to which is connected a comparatively stout but nevertheless yieldable lift spring 80, having an upper loop which is suspended from the hooked extremity 85 of a lifting lever 88 pivoted'at 61 in a stationary portion of the printer structure.

Lever 68 is of the third class type since t e lifting force is applied thereto at an intermediate point in its length by means of a roller 88 which is carried at the end of one arm 89 of a bell crank lever whose other arm ll, having an integrally associated bracket 12, carries two rollers l3 and 14. Of these, roller 13 is actuated by the periphery of an initially effective operating cam 15 carried upon the auxiliary shaft 16 while roller I4 is confined within the trackway of a side channel cam 11, the two cams functioning Jointly in a manner fully described in said copending application.

Auxiliary shaft 18 and the principal control shaft 18 receive their power from drive worm 36. which is carried by the motor shaft, through a gear train which includes the primary diven gear 18, a driving gear 8i integral therewith and a secondary driven gear 82 carried by shaft 16 and meshing with the just described driving gear 8|. Cam I! is dependent for rotation upon tooth clutch 83, a positive saw-tooth driving coupling which is brought into driving engagement under the supervision of a trip lever initiated by a cam carried upon the upper end of shaft 18. said cam being part of a driven sleeve described in greater detail in said copending application, and dependent for rotation upon the friction clutch comprised of the two discs 84 and 85, the assembly of cams 81 being free to rotate upon the release of stop arm 86. Shaft I8 rotating at all times under the influence of driving worm II imparts rotation to its associated apparatus only upon the release of friction clutches 84 and II to impart rotation to the cam assembly 81 and through the teeth of clutch 88 to impart rotation to the aforedescribed cam ll.

Though type wheel shifting frame ll is lifted to variable extents by arm 88, spring I and bell crank 88 as Just described, the degree of movement on the part of the lifting levers is' always the same. The extent of rise on the part of type wheel II is determined by the position of a pair of stop lugs indicated 88 and II, Figs. 1 and 5 to 8, which lugs are capable of being variously arranged so as to engage one or the other of the stop shoulders 58 and Bi already described. It will be observed that lug 8| is the lowermost one and also that it is substantially wider than is the upper lug 88. When both lugs 88 and 8| are in the leftward position as indicated in Figs. 1 and 5, then a condition obtains whereat type wheel II will be permitted to rise only to an extent which will align its upper row of characters II in printing position opposite the platen l4 and printing ribbon 2 l correspondingly, when both lugs 89 and 8| are moved intothe intermediate position, engagement by shoulder 8| will be had permitting the type wheel H to rise until its second row of characters I! will be brought into printing position as shown in Fig. 6. When lug BI is moved to the extreme right so as not to be engageable by either of the shoulders 58 and BI and when under this condition lug 89 is permitted to assume its left-hand position such as viewed in Fig. 7, then the type wheel II is permitted to rise until its third row of characters I2 is brought into printing alignment. Finally when with lug 8| still at the extreme right and the upper lug 88 is brought into the intermediate position, type wheel ll may be permitted to rise in response to the lifting apparatus until the lower or fourth row of characters I2 is brought into printing alignment as shown in Fig. 8.

There will now be recited a description of the apparatus which, in response to line signals, controls the disposition of the lugs and 9| to effect the four designated case shift conditions which will be referred to for convenience as the first, second, third, and fourth shift positions in an order corresponding to the aforerecited description and also to correspond with Figs. 5, 6, 7, and 8, respectively.

Shift plate 52 is threaded to receive two stud screws 92, the latter being preferably of the shoulder screw type with neck portions of sufficient length to be able to receive and support thereat the main body portion 93, Figs. 3 and 4 of lug 89. Also threaded into plate 52 are a pair of shoulder screws 84 whose necks are of suflioient length to support freely the body portion of lug 9| which member includes also an upwardly extending projection 98, Fig. 1. A tensioning spring 91 having one end looped around an anchor post 98 integral with member 95 and its other end loop secured to the anchor post 88 which extends from a stationary part of the machine, tends to urge lug BI and its main body portion 95 toward the left as viewed in Figs. 1 and 5 to 8. This influence is overcome selectively through the instrumentality of bell crank member lUl-IM. One arm III! of said bell crank engages the aforedescribed upstanding lug 88 of member 85, while its opposite arm is engaged by a lever arm I03 under conditions which will now be described. Bell crank lll|ll)2 is pivotally supported by screw is which, it will be recalled,

is carried by the shift plate I! and particularly in a horizontally extending platform I thereof.

A lever ill of which arm III! is an integral portion constitutes one of a set of six storage members indicated in Figs. 2, 3, and 4. Of the set, however, lever I" is the only one having the configuration indicated, the remaining levers I being similar to each other but differing in contour as may be noted in Fig. 2. Certain common characteristics of all of the levers Ill! and Ill! include their alternatively selectable positions determined by the engagement of their stop projection Ill with one or the other of a pair of limit pins I08 and IIII, and their latch arm Iii through which they may be retained in one or the other of their alternative positions by a looking bail HI. When latching or locking bail III is withdrawn, as illustrated in Figs. 2 to 4, which is its condition during a brief signal transfer interval, each lever ill and I" is capable of assuming either one or the other of its alternative positions and, in response to a received code combination signal, a corresponding set of conditions is imparted to the set of levers I and I06 by means of a set of positioning swords 3, flat steel members with'blunt extremities ill, and universal connection discs llli. Beyond this point, the selector mechanism generally indicated III is the same in structure and operation as that disclosed in the aforementioned copending application, save that whereas the distributor cam assembly H5 in the instant apparatus is provided with six setting cams H8, the copending disclosure contemplates but five.

While all of the general class of storage elements I08 are capable of assuming one or another of the alternative conditions in accordance with the conventional operation of printing telegraph apparatus, lever I05 having particular significance to the present invention may also assume a right or a left position in accordance with the setting it receives from its associated sword H3. The illustrations in Figs. 3 and 4 show lever iii! in the counterclockwise position; that is, with its lug lll'l abutting the right side stop pin I09. The opposite or lefthand position of member "i5 is indicated in Fig. 2. With a given setting or presentation of pivot screw 53, it will be understood that the alternative positions of lever arm I03 may be made to effect alternative positioning of hell crank IGI and through it, in turn, to cause to be shifted through upstanding lug 98 the horizontally shiftable body portion ill of shift controlling lug 9i.

Accordingly, with lever I05 in its spacing condition, as illustrated in Figs. 3 and 4, bell crank Hil is maintained in its clockwise extremity with arm I02 urging against the upstanding lug as and maintaining body portion 9| so that lug 8| seeks to achieve its right-hand extreme position, as illustrated in Figs. '7 and 8. This condition prevails so long as selector N5 is in its spacing condition notwithstanding the two possible conditions of shift plate 52. However, when pivot 51 is moved (along with shift plate 52) toward the left, Fig. 6, projection 9| may then assume an intermediate disposition as shown.

Lug 89 which is carried as an integral member of plate 52 is shiftable together with that plate so that it may assume either one of two alternative conditions as illustrated, for example, in

Figs. 5 and 8. Because, however, elongated slot II. Fig. 1, is of limited extent only, the shifting of plate 52 leftwardly as for the W of placing projecting lug u to align vertically with shoulder II will also modify the placement of projection ll through the engagement of the end of slot 56 with bolt 04 so that there is obtained ultimately a condition such as that illustrated in Fig. 6. But, it is to be understood that plate 52 may exert an influence on the disposition of member only when said plate I! is moved to its extreme right-hand position and when, under the circumstances, member ll seeks to attain its extreme left-hand position. As a result 01 these efforts. plate I2 will be moved to its extreme right-hand position under the influence of selectable element 43, but member I will be limited in its effort to achieve its lefthand position because of the restrictive nature of slot 58 which will permit said member to move leftwardly only to an extent where its projection 9| will assume the condition indicated in Fig. 6.

Recapitulating, selectable elements II and 44, acting through the medium of levers I5 and ll, move plate 51 and together with it the projection 89 into either of two alternative conditions, as exemplified in Figs. 5 and 6, Fig. 7 being, so far as projection 89 is concerned, similar to Fig. 5. Selectable element I05 having two alternative conditions and acting through hell crank I Iii, spring 91 being a return agency, is enabled to move member 95 and through it projection 9| into either of two alternative conditions, as exemplified by Figs. 7 or 8 on the one hand and Fig. 5 on the other. The intermediate condition of Fig. 6 is attained when plate 52 is in its extreme right-hand position and member 95 seeks to achieve its extreme left-hand position. As a result, member 95 is intercepted in its path of progress because of the restriction by elongated slot 56 and is permitted to move only to an intermediate position, as illustrated in Fig. 6.

It is therefore to be understood that a total of four case shift selections may be achieved in response to (1) the two standard case shift signals conventionally used for elevating a type wheel in the manner described in the copending application referred to above, and (2) an additional or secondary case shift in response to the sixth code impulse which effects corresponding positionment of the storage element I05.

First modification Figs. 9 and 10 illustrate a modified form of signal transmission system for effecting the control of a double character shift supervision (a total of four shift positions) after the manner of the preferred embodiment described generally above. Contrasting with the system already described, this modiflcation contemplates the use of a five-unit line signal code instead of a sixunit code, th secondary shift signal characteristic being inherent in the nature of the polarity of marking impulses instead of the marking or spacing nature of the sixth pulse. It is proposed, accordingly, to make available for signal transmission both positive and negative current potential, either one of which is to be used permutatively with no-current to produce five-unit Baudot permutation code signals, but whether the marking signals are constituted of positive current or of negative current will determine the alternative characteristic of the secondary shift control.

In the diagrammatic representation, Fig. 9,

the reference character I2I denotes a transmiting distributor of the rotary type which may be' ment I34 which, in turn, introduces correspond-- ing current condition to the marking signals, as will now be described.

The tape transmitting apparatus I22 may be of any conventional type, one embodiment being illustrated in U. S. Patent No. 1,661,012, except that instead of providing but five sensing levers and associated electrical contacting apparatus, unit I22 may correspond in all respects thereto so far as the conventional feeler levers I24 are concerned, special i'eeler I23 being simply an additional member and having an additional pair of contacts with separate contacting points represented by the rectangles I25 and I25. The cable I23 contains five lines, each connecting one of the feeler lever contactors I24 with its associated segment in distributor ring I23. A conductor I3I connects special feeler contactor I23 with one terminal of the winding of a polar relay I32. Continuing from the other terminal of polar relay I32 is a line conductor I33 leading to a special segment I34 of a distributor ring I35 adapted to be bridged by a pair of brushes I35 with the grounded ring I31.

It is to be noted that the aforementioned segment I34 aligns with and corresponds to the distributor cyclic period coincident with the conventional start segment I33 of distributor ring I23 and that this cyclic interval is in advance of the first one of the five permutation code segments of ring I23. For this reason, it will be observed, the operation of relay I32 will occur in advance of the time that brushes I33 encounter said permutation code segments of ring I23. Thus, the transfer operation on the part of relay I32 is made to occur during a no-current interval of the line conductor I43 (segment I33 having no connection with any of the feelers) and there is in this way prevented the possibility of foreshortened or clipped impulses, a result which might not be avoided save through the utilization of a neutral interval during which to exercise the current reversal.

The normal position of tape feelers and their associated contacts I23 and I24 may be supposed in the manner illustrated in Fig. 9; that is, with their contacts engaging terminal blocks I25 and Ill. Accordingly, when presented against the surface of the tape, said contacts I23 and I24 seek to engage the contact blocks I26 and I21, those encountering perforations being permitted to do so and accordingly connecting their respective segments of ring I23 with block I21 which, in turn, receives current potential over a conductor I42, contactor I43 from one or the other of a pair of opposite current sources I44 and I45, Those not encountering such perforations, however, will, during the critical portion of the signal transfer, fail to obtain current and hence cause to be conditioned their respective segments of ring I23 without electrical potential or with no-current.

Relay I32 being of the polar type as already mentioned, its armature I43 will move to the ri ht or to the lett engaging the contact'points I43 or I41 in accordance with the nature of current coming over conductor ill from contactor I23 which may engage positive current block I23 or negative current block I25. When placed in either of its positions, armature I43 remains until altered by an opposite polarity introduced into the windings of its relays I32. Accordingly, it will be understood that the presence or absence or a sixth perforation will correspondingly impress block I21 with positive or negative current and that on this account, permutation code signals generated over ,the segments of ring I23 may be either positive and no-current or negative and no-current and that they will according- 1y be issued out over line conductor I43.

At the receiving station, there is connected to line conductor I43, in series, the selector magnet I43 and a receiving polar relay I5I whose armature I52 will engage or withdraw from its contact point I53, depending upon whether the marking impulses of the received signals are of positive or negative polarity. In accordance with the movements of armature I52, operating current will be introduced to or withheld from the winding of the secondary shift control relay I54, over an obvious circuit, Fig. 9.

A bell crank armature I55 pivoted at I53 and responsive to the energization or nonenergization of relay I54 actuates an intermediate bell crank lever I51, resembling in appearance and operation the bell crank lever IIII discussed in the preferred embodiment above. The actual relationship and position of bell crank lever I51 is as illustrated in Fig. 10, whereat its vertically extending arm engages a projection I53 integral with the horizontally shiftable bar I53 whose interponent lug IIiI corresponds in appearance and operation to the lug 3I of'the preferred embodiment.

Bar I53 will be supported in the same manner as bar 35 of the preferred form; that is. by a shiftable plate, such as plate 52, and will be capable of responding in the same manner as the other member. Likewise, a lug I32 corresponding to the described lug 33 will be provided and will also be carried by said shittable plate, the two lugs iii and I62 to function under the control of bell crank I51 in a manner and for the purpose already described in the preferred embodiment.

Since the operation of secondary shift control magnet I54 by the current characteristics as aforedescribed need not be established except during any one impulse of a signal, and since the most favorable opportunity for executing the performance (energization or release) of said magnet I54 is coincident with the stop (R) impulse interval, means have been provided for shunting the supervisory polar relay I5I so that it may not fluctuate except during the precise interval coincident with the stop signal impulse. This supervision is exercised by a special cam carried upon the distributor shaft I53 which, acting through a follower lever, causes the contact pair I50 to come ajar during the distributive interval coincident with the stop impulse, thereby removing the shunt ground from a local circuit as shown in Fig. 9 cutting into circuit relay I5I together with magnet I43 and permitting both members to respond to the stop impulse. At all other times in the distributive cycle, howeventhe apex of said cam of the distributor shaft III is withdrawn from the follower lever permitting contact pair III to engage and to thereby effectively shunt relay I II out of the signal responsive circuit.

It is to be understood, therefore, that the modified showing of Figs. 9 and 10, illustrates another manner of controlling the functioning of a secondary shift control structure but, in this case, under the supervision of a five-unit code instead of a six-unit code as contemplated in the first described system. A shift characteristic for the purpose of supervising a secondary type wheel shift function has been embodied into the standard five-unit code by alternating the current characteristic of the marking impulses between plus and minus, the spacing impulses being in all cases no current.

Second modification In Figs. 11 and 12, there is illustrated a further system of printer control and line transmission for utilizing the five-unit Baudot code signal in such a manner that it will afford sixunit signaling possibilities. Other manners of accomplishing this result have already been disclosed in connection with the embodiments described above, as by providing means for supplying two current conditions for the marking impulses.

In the manner of signaling contemplated in connection with the present embodiment, there is employed a five-unit Baudot type code combination signal having, in addition to the conventional five selective impulses, a special impulse utilized for supervising secondary shift control and a start impulse interval of a polarity opposite to that of its preceding or special impulse interval, under the specific contemplation of the five code combination impulse interval.

In other words, whereas conventional five-unit permutation code signals being provided with seven componential impulse intervals contemplate start and stop impulses of predetermined and invariable line characteristics, means are herewith provided for varying the characteristic of the stop signal interval so that it may have utility for selection as well as phasing supervision and for making the start initiating apparatus responsive to a start impulse condition of electrical polarity opposite to that of the immediately preceding stop impulse interval which, as has been said, may consist of either one of two alternative line conditions.

In the incorporation of this plan of operation, it has been found expedient to utilize plus and minus current conditions to represent marking and spacing instead of the conventional practice of utilizing current and no current conditions for this purpose. Moreover, as in the case of the first modification, Figs. 8 and 18, there will be utilized for the purpose of signal translation a six feeler sensing apparatus generally indicated by the reference character I1I. Reader mechanism "I is illustrated as having seven contactors I12 to I18: however, contactors I11 and I18 both are carried upon a single feeler lever while each of the remaining contactors I12 to I18, inclusive. is carried individually upon a feeler lever.

In accordance with the operation of its feeler lever, each contactor is spring urged so that it will engage the contact block towards the right and is capable of movement in an opposite direction so as to engage the contact block towards the left, as illustrated in Fig. 12. The contact block at the right is comprised of a large section indicated I18 and a smaller section insulated therefrom indicated I8I. The contact block at the left is similarly comprised of two sections, the larger one indicated I82 and the smaller one I88. Moreover, as may be noted the small contact block I88 is connected electrically over an obvious conductor with the large contact block I18 and correspondingly small contact block I8I is connected electrically with the large contact block I82. Opposite sources of grounded potential indicated I84 and I85 are connected respectively to the contact blocks I88 and Ill, over conductors I88 and I81 to the oppositely placed contact points of armature I88 under the control of a polar relay I88.

The winding of said relay I88 is connected at one end to the aforedescribed feeler contactor I18 and at its other end to a distributor segment I8I situated in distributor ring I82. This distributor I88 which includes also distributor rings I88, I84, and I85 is of the start-stop type having a brush carrier I81 which supports two pairs of bridging wipers I88 and I88. Brush carrier I81 of transmitting distributor I88 is conventionally illustrated in Fig. 12, but it is to be understood that this element is driven through a friction coupling preferably in a rotary direction and that it may be restrained from movement by the intervention of an armature 28I under the supervision of start magnet 282. Also, that the pair of wipers I88 serve to connect segmented distributor ring I83 with the solid distributor ring I84 which is electrically connected to line conductor 288, and that the pair of wipers I88 correspondingly connect distributor ring I82 which contains the segmentI8I aforedescribed with the grounded distributor ring I85.

Attention will now be given to distributor ring I88 which, as may be observed in Fig. 12, is made up of seven segments. When the brush carrier I88 is in its arrested position, wiper I88 is contacting the slightly longer segment designated 5 in the distributor ring I83. Also, it may be observed that following the segment 5 which serves also in the capacity of a stop segment as will later be described, there is encountered a start segment designated by the character S.

Following this segment is one designated 0 (zero), when has been arbitrarily assigned to the function of supervising the secondary shift. This control is otherwise executed, in accordance with the present embodiment, in a manner generally similar to that described above in connection with the preferred embodiment.

The remaining segments 1, 2, 3, etc., including segment 5, which as has already been stated. functions in a dual capacity, serve to distribute those signal impulses which relate to the composition of the permutation code. Segment 5 is connected over a conductor 284 to the feeler I11. Se ent 8 is connected over a conductor 285 to the armature I88 of polar relay I88. Fig. 12 illustrates diagrammatically transmitting station equipment including a perforated tape controlled mechanism and a rotary signal transmitter under the supervision thereof for issuing signals of a type adapted to exercise the control function including primary and secondary shift supervision for printing apparatus having mechanically the characteristics exemplified in the showing of Fig. 11.

As the brush carrier Ill proceeds in the downward direction as indicated by the arrow Ill, the pair of wipers Ill leave segment No. l and encounter segment bridging this element of distributor ring Ill with the solid line ring Ill. Assuming, for the sake of illustration, that the perforated tape sig al which has Just been pogrounded at the receiving station. As the brushes proceed-to the next segment which is designated 8, opposite polarity is issued from grounded battery Ill if polar relay' Ill, in accordance with its preceding operation, has been left in a position whereat its armature Ill engaged the contactor of conductor Ill. This circuit is traceable from negative battery Ill,. conductor Ill, armature Ill, conductor 205, segment S of distributor ring Ill, brushes Ill to line ring Ill.

If instead of the supposed example described above, the particular signal had been one in which the feeler lever with which contactors Ill and Ill are integrally associated was positioned to the left causing engagement with contact block "2 and Ill instead of contact block Ill and Ill, the electrical characteristics relativeto segments I and 8 would be opposite to that Just described. With the brushes Ill passing over segment 5 negative potential would be supplied from grounded battery Ill, segment IlI, segment I", feeler Ill, over conductor 2 to segment No. 5. Likewise, positive current would be supplied from grounded battery Ill, conductor Ill, armature Ill of polar relay Ill, which has been energized to its opposite position, conductor 2" to segment S of distributor ring Ill. Each of the feeler contactors "2 to Ill, inclusive, is connected over an individual conductor with an associated segment 0 (zero) to 4 of the transmitting distributor ring Ill. Accordingly, when a feeler lever encounters a perforated position in the tape, its contactor will be moved into one position, say the right-hand one, engaging the contact block Ill while its said feeler lever encounters a nonperforated position and its contactor will assume an opposite condition; that is, contacting the opposite .block Il2. The designation of plus or minus signals to correspond with perforated or nonperforated signal components is arbitrary, and it is to be understood that the reverse association is equally feasible.

The foregoing is true not only of the conventional flve feeler levers of contactors I12 to Ill, but also of the special feeler lever with which are associated two contactors Ill and Ill, as has already been mentioned. One significant difference, however, does prevail which will-nowbe noted. In the case of the special or sixth feeler lever, when a perforation is encountered and, say both contactors are moved to the right, contactor Ill will be introducing negative current from battery source Ill to the winding of bias polar relay Ill while contactor Ill will be introducing positive battery from source Ill over conductor 2 to the stop segment 5. Conversely,

with the contactors Ill and Ill in the O site position, that is, engaging contacts blocks "2 and Ill. positive current originating from source I ll will be introduced through feeler Ill to the winding of bias polar relay Ill, while negative current originating from source Ill will be introduced over conductor III to stop segment 5. 'Accordingly, since armature I ll of relay Ill is connected to the start segment 8, the result of the operation of the sixth or special feeler lever will be understood as one controlling the reversal of potential for start segment 8, that isto say, with a given condition on the part of segment 5 which may be either plus or minus the sixth feeler lever controlling contactors Ill and Ill operate to provide an opposite current potential to the start segment 8.

The purpose in having provided polar relay Ill with its armature Ill connecting plus or minus current to the segments instead of directly connecting the contactor Ill to said segments is one of permitting the start impulse signal interval to be stored. The transmitter utilized is of the well-known magnet type wherein a new signal is sensed during the start interval. If a new signal should be sensed which would cause the feelers Ill and Ill to move to their opposite position the start impulse would be of the same polarity as the stop impulse. However, by providing the polar relay Ill, the armature Ill will be held in a position whereby potential opposite to that of the stop segment 5 will be assured, as

v the armature Ill retains such position until the paratus responsive to thesignals generated by the transmitting distributor Ill. Of these, the

reference character 2ll denotes a bias polar relay whose armature 2ll' is grounded, and is adapted to reciprocate between two contact points 2ll and 2 which are part of a local circuit for supervising the operation of principal control magnets 2I2, see also Fig. 11.

Also situated in said receiving station local circuit are a. pair of contactors indicated 2Il and 2. The. former reciprocates between a pair of contact points 2Il and 2Il and the latter between a pair of contact points 2i! and 2Il. In the printer apparatus which is shown in mechanical detail in Fig. 11, contactor 2I| and its associated contact points 2i! and 2Il are indicated as an assembly controlled by a follower arm 22I pivoted at 222 and supervised by a cam apex 228 which is one of an assembly carried upon the distributor cam shaft ll, see also Fig. 1. Also carried on shaft ll as an integral part of the aforementioned cam assembly and in addition to the aforedescribed cam having the apex 223 are five selector signal cams whose apices actuate the five bell crank levers 224 mounted in pivotal alignment upon shaft 222 and hence affording visibility only. to the foremost ones in Fig. 11.

a sixth cam similar to said the distributor cams is utilimd for the purpose of actuating the storage lever Ill which is similar to the one described in connection with the preferred embodiment above and which actuates in a similar manner a bell crank III for the purpose of obtaining the referred to secondary shiit control. In additon to the cams already designated in the assembly carried by shaft 19 is one indicated 223, having a plurality of spaced spices, which when said cam assembly is rotating, serve to rock the armature bell crank 22! about its pivot 223 for the purpose of presenting its magnetically attractive arm 229 against the polar face of magnet 2|2. This operation of cam 226 in assisting the armature 221 and thereby diminishing the work of magnet 2|2 is in accordance with recognized practice in printing telegraphy.

As illustrated in Fig. 11, storage lever llll is disposed below the other storage levers 23l and 232. This arrangement is in a general sense arbitrary for the shift signal impulse, in the particular instance corresponding to the segment on the distributor ring I93, Fig. 12, may be located if preferred in any other position with respect to the componential sequence both in the distributor ring I93 as well as in the stack of selector storage levers, Fig. 11, designated I35, 23l, and 232. Storage levers 232 are five in number corresponding to the signal components which utilize the seg ents 1, 2, 3, 4, and in the transmitting distributor ring I93. Storage lever 23l, together with the top one of levers 232, correspond to the code signal impulse occupied by the segment 5, and in the order designated each impulse ultimately serves to place its associated lever 23| or 232 in one or another of its two possible positions as already described in connection with the preferred embodiment.

For the purpose of understanding the principles of the instant improvement, it will sufilce to state that ultimately the storage signal is manifest by a conditioning of the several storage levers I95, 23|, and 232 with the lever I05 exercising the function of controlling secondary case shift bell crank Ill and 1evers-232functioning to condition the set of code discs 234 which are five in number.

Storage lever 23| controls the shifting of abovementioned contactor 2|3. Accordingly, when it is found in the position as illustrated in Fig. 11, it permits contactor 2|3 to engage its upper contact 2l9, and when it is in an opposite condition such as that occupied by the counterclockwise extreme storage lever 232, in Fig. 11, said lever 23l by its protuberance 235 will engage the insulated extremity of contactor 2|3 and thrust the latter member so that it will disengage contact 2|9 and engage contact 2|9 instead.

A supervision of contactor 2 is had by follower lever arm 22l under the control of cam apex 223, that is, when apex 223 is in the position indicated, contactor 2l4 is thrust against its left contact 2l5 but at all other times, that is, when apex 223 is clear of the follower arm 22l, contactor 2 is permitted through its own spring tension to recede from contact point 2|! and to engage instead contact point 2I9. There will now .be described the effect of the supervition of contactors 2|3 and 2l4 by the abovedescribed apparatus.

Let it be assumed for the sake of illustration that a particular code signal transmitted over distributor I99 is comprised of a certain combination of code impulses whose fifth component (three being a total of six components including 0) is constituted of marking characteristics, that is, the current characteristic which will position its sword 233 in the manner indieated in Fig. 11 so as to place storage lever 2" in the position indicated in this illustration. Accordingly, contactor 2" will be permitted to recede from contact point 2|3 (assuming that a preceding signal dlflered in respect to this signal component) and to engage instead its contact 2". This will correspond also to the placement .0! contactor 2|4, as illustrated in Fig. 12. In order to produce this result, the nature of the si nal impulse will be such as to eiiect the polar relay 231 to cause it to move its armature 293 to engage contact point 233 so as to open the circuit for selector magnet 2|2 and to cause the armature 233, Fig. 11, to assume its marking position. Subsequently, there will follow the start signal impulse whose eifect upon relay 201 will be opposite to that just described in connection with the No. 5 signal impulse, which reversal is assured by the apparatus of the transmitting distributor described above. In consequence, relay armature 203 will be moved counterclockwise to engage its contact point 2| l, as illustrated in Fig. 12 closing the circuit for energizing selector magnet 2|2 and thereby releasing the selector apparatus for a given cycle.

Under the alternative condition of operation, that is, with the No. 5 impulse being of spacing nature, contactor 2|3 will be withdrawn from contact point 2|9 and thrust into engagement with contact point 2|3 instead. As described in said copendlng application, referred to above, cam-shaft 19 carries in addition to the aforedescribed operating cams 223 and 226, a spiral distribution of cam apices indicated 239, live in number. Each one of these is related to one of the signal impulses l to 5, inclusive, whose corresponding segments appear ln the distributor ring I93, Fig. 12, while the final one of said series specially designated 230A, Fig. 11, is, in accordance with the present embodiment, of double width.

This is so because unlike the other of the cams 239 which serve to actuate but a single one of the claw levers 224, it alone actuates a pair 01' said claw levers 224. Since said levers 224 are all of the same contour, they may not be differentiated in the showing of Fig. 11, however, on account of the spiral arrangement of said cams 230, each claw lever 224 will be operated at a particular cyclic interval, except said two claw levers 224 which are operated in unison by the special apex 230A. Each claw lever is provided with a sword 233 but the sword which is associated with the anterior lever 224, as viewed in Fig. 11, has been specially designated 233'. Each sword 233 and 233' terminates with a blunt point projection which rests against one side or the other of a hump 239 of an intermediate lever element, five of which are designated 232 but the one related to the sword 233 of which is designated 23l. The five similar levers 232 each are provided with a tail piece 239 that serves as a locking projection by being placed on one side or the other of a looking bail 2", which member assumes the position indicated in Fig. 11, except during a brief interval following the conclusion of a particular signal when its lever arm 242 is released by the operation of the aforedescribed auxiliary shaft 13.

Accordingly, while the several swords 233 and 233' may assume one position or the other as its abutment 243 Or 244 encounters the downwardly extending vane 243 or 243 of armature 236, levers 23| and 232 may not be correspondingly positioned until said swords 2'33 and 233' v arsthrustdownwardlybythsclookwisemovement of the claw levers III, which movement is urg d by their individual springs 24! as well as by auxiliary individual springs carried upon an integral extension of lever arm 242.

The auxiliary springs of lever arm 242 are not shown in Fig. 11 of the drawings, but reference may be had to the aforedescribed copcnding application where it is explained that their function is of an auxiliary nature and to assist the principal actuating springs 241. None of the sprin 2" or th a xiliary springs mentioned may actuate their associated claw levers 224 during the time that the locking ball 2 intervenes by blocking the extending portions 229 of levers 222. However, since lever III \is not provided with an extension 222 as are the remaining ones of the levers designated 232, its response to its associated sword 222' will occur immediately following the instant when cam apex 220A the follower projection of claw lever 22 which carries said sword 222'.

Thus, while the consummation of a signal transfer relating to a particular set of code impulses of any signal must await a brief interval following the fifth or stop code impulse, the actuation of contactor III by the projection 22! of special storage lever 22l follows immediately upon receipt of the fifth code impulse. This assures the operation of selector magnet M2 for the P p se of arresting the rotation of shaft 12 coincidentally with the signal interval corresponding to the stop or fifth code combination impulse, even though the other purpose ofthe particular impulse, namely, that of setting one of the code discs 224, may await its regular period of operation which, as has been said, occurs after the lapse of a brief time interval and, in fact, during the occurrence of a succeeding code combination signal.

Cam apex 222 is specially provided for the p p e of actuating the aforedescribed arm 2" which, in turn, controls contactor 2 I. can apex 222 is effective to thrust contactor 2 against its contact point 2 II for a period commensurate approximately with the beginning of the stop or No. 5 code combination impulse and continuing through the start impulse S and to the (zero) or shift controlling impulse. At other times contactor 2", see also Fig. 12, engages its contact point 2lt for a purpose which will now be described.

Operation of the second modification Concisely stated, armature 2 of relay 2!! fluctuates in accordance with each signal impulse, contactor 2 ll being controlled by cam apex 222 rests against contact point 2|. at all times except during the stop and start signal interval, and contactor 2|! being controlled by the No. 5 or stop signal is moved into one or the other of two alternative positions as a result of the operation of the transfer mechanism, described above, only during the period corresponding to this impulse. Under an assumed set of conditions, in response to marking signals, both armatures 202 and 2|! will be deflected downwardly, that is, to engage their contact points 2 and 2", while under spacing signal impulses, said armatures will be in their opposite position, that is, engaging respectively their contact points 209 and 2|. Also, it is to be recalled that since the No. 5 impulse functions in a dual capacity of eflecting the distributor stop control as well as of entering eluding No 5 impulse, because it. together with the impulses No; 1, 2, 3, and 4, comprises the code combination of the particular signal.

Accordingly, when the No. 5 impulse of a preceding signal happens to be marking. armature 2|! will be thrust into en ement with its contact point 2, contactor 2 will be thrust into engagement with its contact point 2| I (on account of the operation of cam 22!), and contactor 212. as a result of the transfer operation, will be moved into engagement with its contact point III. This will complete a circuit traceable from grounded battery at 2M, winding of magnet 2l2, conductor 2", contactor 2". and its contact point 2" with which it is then in engagement, conductor 2", contact point 2| I, and its armature 2" which is then in engagement with it to ground. As a result of the continued energizetion of magnet 2 l2, its armature is held and the rotation of shaft I8 is arrested in accordance with the conventional operation of printing telegraph selector shafis. This condition continues until the circuit for energizing 2|2 is broken, which change occurs upon the receipt of a proper start impulse over segment 8 of transmitting distributor ring Ill. The polarity of the start si nal being opposite to that of the No. 5 or stop signal impulse, as already explained, causes armature 208 to be moved to e e its contact point 2" and away from its contact'point 2. This interrupts or open; the circuit for magnet 2l2, causing the release of its armature 236 and consequently initiating the rotation of receiving distributor shaft 12 in a manner clearly described in the copending application referred to.

As distributor shaft 12 rotates, cam apex 223 rides of! the projection of arm 22| permitting contactor 2 ll to be drawn away from its contact point 2|! and to come into engagement instead with its contact point 2ll, meanwhile contactor 2|; remaining in engagement with its contact point 2|! because it can be changed only during the occurrence of the fifth impulse. As a result of the change in contactor 2 I I from contact point 2|! to contact point 2l8, no effect is obtained at this time, magnet 2|2 continuing to be deenergized until din-ing the course of the succeeding six signal impulses, 0, 1, 2, 3 etc., armature 208 in response to its relay 20'! returns to engage its contact point 2| l, which response can occur only under the control of marking signal impulses.

In the event that a marking impulse is received during the 0 (zero) impulse interval, the

action of one of the swords 222 upon the storage lever III! will cause bell crank llll to be rotated clockwise in a manner and for the purpose already described in connection with the preferred embodiment above. In the event marking impulses are received for any of the other impulse intervals 1 to 5, inclusive, their storage levers 23l and 222 will be accordingly positioned, causing corresponding placement of the several code selector discs 2 after the selection has been completed and the transfer mechanism operated, but of particular significance in this connection will be the current characteristic of the No. 5 signal impulse.

If this signal impulse is again marking in nature, the succeeding operation will be the same as the one iustdescribed except for the variations which may occur in the code combination, but if instead the signal impulse corresponding to the No. 5 interval happens to be of spacing nature,"

then armature 208 will respond by eng ng its upper contact point 2" and sword 222' will be disposed in the manner illustrated in Fig. 11. As

' a result of the latter incident, contactor 2|! will tactor 2M and its contact point 2|, conductor- 2", contact point 209 and its contactor 20! which is then in engagement with it, to ground.

As a result, magnet M2 is held energized which is the proper condition corresponding to a stop impulse until an opposite current condition is received by relay 201 causing its armature 208 to be withdrawn from contact point 208 and to engage instead contact point 2. When this occurs, contactor 2 is still held in engagement with its contact point 2|! because of the described function of cam 222, which maintains said condition until after the interval corresponding to the start, 3, impulse. Meanwhile. the last described movement oi armature 208 causes the energizing circuit for magnet M2 to be broken and accordingly releasing its armature 228 for the purpose of initiating rotation of receiving distributor shaft 18, as aforedescribed.

Thereafter and coincident with the (zero) signal interval. apex of cam 223 restores contactor 2 to it condition prevalent during the major portion of the cycle; that is, engaging its contact point 2l8. when this occurs, that is, when armature 208 of relay 20! engages contact point 2, marking impulses are thereafter interpreted as magnet 2 l2 energizing impulses. because contactor 2 ll continues in engagement with its contact point 2|8, causing the magnet 2l2 energizing circuit to be completed over the following described course. The current originates with grounded battery "I through the windin of magnet 2 l2, conductor 252, contactor 2", and its contact point 2 l 9, conductor 2". contactor 2 l4 and its contact point 2", conductor 2", contact 2| I and its contactor 208, to ground. Thus, phasing of the receiving magnet 2l2 as well as of its controlled shaft I8 is regulated notwithstanding the reversed condition of the No. and start impulses.

While the foregoing description has been explained and described with reference to specific embodiments, it is not intended to be restricted in any manner to the language of the detailed specification nor to the illustrations in the accompanying drawings, except as indicated in the hereunto appended claims.

What is claimed is:

1. A control mechanism for type wheel printing machines having four printing positions,

aasso switch responsive to the anal impulse 0! a series of impulses comprising a signal for preparing one of said two alternative circuit paths to said magnet, and a shunting switch eitectivefdurin certain other signal intervals only of a series for so preparing the other of said paths.

3. In a receiving selector mechanism for telegraph printers, a selector mechanism control magnet, a line relay having an armature responsive alternatively in accordance with received signal impulses, a pair or electrical circuits communicable with said line relay armature for establishing connection with said receiving mag-. v net, a contactor responsive to a predetermined signal impulse translated to said magnetior- 'selecting one of said two circuits and for conditioning it in contemplation of a succeeding signal, and means eii'ective during an initial period of each signal for shunting both said circuits to make either effective to the performance or said line relay armature. 4. A mechanism for eilectingsupervision or four case shift conditions comprising, a first case shift regulating member responsive alternatively in accordance with a pair of code combination signals, a second regulating member responsive alternatively to a pair of single impulse conditions, and means for yieldably moving a shittable case member to encounter one or the other of said regulating members.

5. In a receiving station apparatus, a selector magnet responsive to current impulses for releasing i'or rotation a receiving distributor mechanism and for conditioning a selector apparatus, a receiving line relay ve alternatively to varying line potentials, two electrical circuits connecting a local current supply through said line relay with said selector magnet, a switch responsive to the final impulse of a series of varying line potential impulses comprising a signal for preparing one of said two circuits to said magnet, and a shunting switch eil'ective during certain signal intervals only of a series for rendering said line relay communicative with either or said circuits.

6. In a printing telegraph apparatus, a selector mechanism, a single magnet for initiating said comprising a spring yieldable type wheel lifting means, a frame supporting said type wheel having two abutments, a pair of shiitable abutment lugs each movable into alignment with one or the other of said abutments, means under the control of a pair of code combination signals for supervising the movement of one oi said shiftable abutment lugs, and means under the control of a signal condition collateral to said code combiselector mechanism and for variably operatin it in accordance with alternative line current interval variations, means responsive to certain current interval variations for energizing said magnet and to other currentinterval variations for deenergizing said magnet, and means eii'ective during certain impulse inte of a series only for energizing said magnet in response to either current variations and for deenergizing said magnet in to succeeding opposite current variations.

7. In a system of line signaling, a transmitter station apparatus including a perforated tape control mechanism, an impulse distributor having an element for each of a series of impulses relating to a signal, means responsive to said tape control mechanism to vary the electrical characteristics of marking impulse elements or said distributor, and means for effectuating said a predetermined impulse of a code combination said predetermined impulses, means for supervising a case shift control under the supervision of one code combination impulse and means, for supervising a case shift control under the control of a plurality of said code combination impulses including said predetermined impulse.

9. In a start-stop printing telegraph system, a type shaft, a rotary selector shaft for controlling the position of said type shaft, frictional driving means for rotating said selector shaft, selective means for arresting said selector shaft eifective invariably during a predetermined impulse of each code combination signal and independent of the electrical characteristic of said impulse, control means for disabling said selective means and thereby starting said selector shaft during a succeeding code combination impulse of electrical characteristic opposite to the electrical characteristic of said predetermined impulse, means for supervising a case shift control of said type shaft under the supervision of one of said code combination impulses and means for effecting a case shift control of said type shaft under the supervision of a plurality of said code combination impulses including said predetermined impulse.

10. In a telegraph system, a printing mechanism comprising a type unit capable of assuming four case positions, a selector mechanism responsive permutatively to the impulses of a code combination for controlling the positioning of said type unit among two of its said four case positions, a selector mechanism responsive to the alternative variations of one of the impulses of a. code combination signal for determining the,

positioning of said type unit among the other two of its said four case positions, and yieldable means for moving said type unit to a case position in accordance with the operation of said two selector mechanisms.

11. In a telegraph transmission system, a type unit capable of assuming four case positions, spring urged means tending to move said unit from a normal position to an extreme one of its said four case positions, and a pair of interponent means for intercepting the movement of said type unit under the control of a code combination si nal and also under the control of a characteristic impulse of each code combination signal.

12. In a printing telegraph apparatus, a shiftable case controlling unit, spring intervening means for urging said unit from a normal to an extreme one of a plurality of successive case positions, and interponent means responsive to two different selecting characteristics compositely for varying the extent of movement of said type unit by said spring means.

LOUIS M. PO'IIS. 

